Participation in the treatment protocols of the Pediatric Division of the Southwest Oncology Group (SOG) provides the basis for the clinical research program in pediatric oncology at the University of Mississippi Medical Center. Collaborative studies by the member institutions of the Pediatric Division of the SOG are designed to delineate more effective treatment for a variety of types of childhood malignancies employing chemotherapy, often in association with surgery and radiotherapy. During this year, studies will be in progress for the following types of childhood malignancies: acute lymphocytic leukemia, acute granulocytic leukemia, Hodgkin's disease, Non-Hodgkin's lymphoma, histiocytosis X, neuroblastoma, osteogenic sarcoma, brain tumor, Wilms' tumor (through the National Wilms' Tumor Study), rhabdomyosarcoma (through the Intergroup Rhabdomyosarcoma Study), and Ewing's sarcoma (through the Intergroup Ewing's studies).